This invention relates to a clearance adjuster with which a predetermined amount of clearance between a certain member and another member can be secured with accuracy and ease. For instance, such a clearance adjuster is useful with the control cable of normally non-contacting type clutch system for motor vehicles.
A conventional normally non-contacting type of cable control system will be explained referring to FIG. 1. A cable guide 13 having a through hole 13b is fixed on the body of the vehicle 16. The outer cable 10 is fixed on the clutch housing 1 at its one end, with the other end forming a screw 11, which is attached with double nut 12, said screw 11 piercing through the cable guide 13. The inner cable 4 is connected to the clutch pedal 14 at its one end, with the other end connected to the withdrawal lever 2.
The clutch system as above-described operates in such a manner that, when the clutch pedal 14 is kicked down, the inner cable 4 is displaced relative to the outer cable 10 thereby to rotate the withdrawal lever 2 counter-clockwise in the drawing, around the point 2a. Whereupon the release bearing 3 presses the central portion of the diaphragm spring 5, to release the pressure of facing 6 exerted on the flywheel 9. In assembling this type of clutch system, care must be taken to secure a predetermined amount of clearance A between the withdrawal lever 2 and the release bearing 3, so that the pressure of the facing 6 on the flywheel 9 should be released at the optimum position. Also, since the amount of rotation of the withdrawal lever 2 corresponding to the set degree of movement of clutch pedal 14 tends to vary due to the stretching of inner cable 4 and wear of facing 6 during their use over a prolonged period, the clearance must be adjusted time to time to always secure the proper actions of concerned parts.
For this purpose, in the conventional adjuster the double nut 12 as shown in FIG. 1 or an E-ring (not shown) is used to effect the adjustment.
That is, while the withdrawal lever 2 is kept as pressed against the release bearing 3, the double nut 12 (or E-ring) is adjusted to secure a predetermined clearance A' between the same and the cable guide 13. In that operation, the fixed position of the double nut is determined either by using a gauge of a predetermined thickness or by eye measurement. In the former case the assembling requires much labor, and in the latter case the clearances are not uniform and inaccurate. The assembling becomes relatively easier when an E-ring is used to secure the predetermined clearance. However, because the E-ring grooves are provided stepwise on one end of the outer cable 10, fine and optimum clearance adjustment is impossible. In a worst case a dislocation by one pitch of the E-ring grooves occurs.